The term in-ear device (IED) includes active devices, either of a hearing protection nature, or of a hearing aid nature, in which some or all of the batteries and other components are mounted behind the ear, or remotely, in a box that communicates with the IED unit by means of a sound-tube, or by wires. As such, IEDs include powered, active devices in which a microphone, speaker, and all the associated sound-processing circuitry and components, including a battery, are contained within the in-ear unit. IEDs may also be passive, i.e. not powered, and some simply amount to a plug in the ear. More sophisticated passive IEDs may include acoustic chambers and filters, for passing or attenuating selected frequencies.
Regardless of the active or passive nature of IEDs, it is recognized that the performance of all IEDs is highly dependent upon the fit of the IED in the ear. If the IED is a poor fit, excess or undesired sound may simply by-pass the IED, causing the wearer to hear undesired sounds. The tendency therefore is for the IED to be too tight, which leads to poor wearer-comfort, whereby the wearer tends not to keep the IED in for long periods.
Recent trends in hearing aid IEDs seek to overcome the traditional problems with fit by providing multi-channel sound transmission or by eliminating feedback. Such techniques may be useful for improving quality of sound and reducing feedback. However, since the shapes of the ears of different wearers are not the same, the efficacy of such techniques may not necessarily be consistent from one wearer to another. Further, such techniques may require frequent readjustment of the IED in different hearing environments. Accordingly, it is advantageous to custom fit an IED to the ear of the wearer, on an in-situ basis, to minimize such difficulties.
A variety of techniques and means may be used for custom fitting an IED to ear of the wearer. Such techniques and means include manufacturing the IED directly within the ear of the wearer, use of a deformable stretchable sheath to cover the IED and match the contour of the wearer's ear, or use of molds. These techniques and means are well known in the art.
U.S. Pat. No. 5,006,055 issued to Lebisch et al. on Aug. 4, 1989 discloses an apparatus for manufacturing an IED directly in the ear of a hearing-impaired person with a deformable envelope or sheath being pulled over a die or over a shell or over an overlayed over-shell. However, this rather long and tedious process requires many steps of assembly.
U.S. Pat. No. 5,333,622 and No. 5,131,411 issued to Casali et al. on Aug. 2, 1994 and on Jul. 21, 1992 respectively disclose a custom-molded IED, i.e. an ear plug, that can be used for selecting pre-sized earplugs or as a cast for creating a mold for earplugs or hearing aids. This earplug is not appropriate for custom fitting in-situ of an ear canal of an individual.
Canadian patent application No. 2,302,962/A1 of McIntosh et al. filed on Mar. 23, 2000 and laid open on Sep. 26, 2000 discloses a hearing apparatus adapted to be inflated in-situ using an inflation-medium. The apparatus includes a core portion that is generally covered by a separate sheath. The proper installation of the sheath requires extensive delicate care, especially when bonding the far end of the sheath to the core using the far-seal-means without obstructing the acoustic tube.
In light of the foregoing, it would be advantageous to have an IED that allows for facilitated in-situ fitting. Accordingly, it would be useful to have a means, such as a stretchable sheath, that may be easily employed with an IED to allow simple in-situ custom fitting of the IED in the wearer.